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Abstract:

Complex inorganic titanate pigments with low dopant levels (i.e., less
than about 5%) exhibit coloristic and enhanced infrared (IR) reflectance
characteristics that make them useful in formulating colors exhibiting
high IR reflectivity. This characteristic is becoming increasingly useful
as a way to keep exterior surfaces and articles cooler during exposure to
direct sunlight. Achieving this can decrease energy (e.g., cooling/air
conditioning) consumption and costs. Low-loaded titanates can boost IR
reflectivity by 1 to 10% in selected visual color spaces. Paint
compositions containing those low loaded titanate pigments and a method
for providing a surface with high infrared reflectance utilizing those
pigments are also disclosed.

Claims:

1. Complex inorganic titanate pigments having a loading of coloring metal
ions and their charge balancing ions of less than about 5% by weight, and
an average particle size of from about 0.3 to about 5 μm.

2. The pigments according to claim 1 having an average particle size of
from about 1 to about 5 μm.

3. The pigments according to claim 2 having a loading of coloring metal
ions and their charge balancing ions of no greater than about 4%.

4. The pigments according to claim 3 having a loading of coloring metal
ions and their charge balancing ions of no greater than about 2%.

5. The pigments according to claim 4 having a loading of coloring metal
ions and their charge balancing ions of no greater than about 1%.

6. The pigments according to claim 3 having an average particle size of
from about 1 to about 3 μm.

8. A high infrared reflective paint composition comprising an effective
amount of the pigment according to claim 1, in a paint vehicle.

9. A high infrared reflective paint composition comprising an effective
amount of the pigment according to claim 4, in a paint vehicle.

10. A high infrared reflective paint composition comprising an effective
amount of the pigment according to claim 6, in a paint vehicle.

11. The paint composition according to claim 8 which is substantially
free of other pigments.

12. The paint composition according to claim 8 which is substantially
free of other TiO2-derived pigments.

13. A method of providing a surface with visual color and high IR
reflectance comprising the step of coating said surface with the paint
composition according to claim 8.

14. A method of providing a surface with visual color and high IR
reflectance comprising the step of coating said surface with the paint
composition according to claim 9.

15. A method for providing a surface with visual color and high IR
reflectance comprising the step of coating said surface with the paint
composition according to claim 10.

16. A plastic composition which comprises a plastic base material and an
effective amount of the pigment according to claim 4.

17. A plastic composition which comprises a plastic base material and an
effective amount of the pigment according to claim 6.

18. A composition which comprises a base material selected from concrete,
ceramic and glass enamel, and an effective amount of the pigment
according to claim 4.

Description:

[0001] This application is based on and claims priority from U.S.
Provisional Patent Application Ser. No. 61/505,347, White and Montgomery,
filed Jul. 7, 2011, incorporated by reference herein.

TECHNICAL FIELD

[0002] The present invention relates to the field of color pigments,
specifically color pigments which exhibit high levels of infrared (IR)
reflectance. In particular, the present invention relates to
titanate-based complex inorganic color pigments (CICPs) with low dopant
levels (low loading) and their use in the formulation of high IR
reflective materials which can be used to color substrates such as
plastics, paints, coatings, ceramics and glass enamels.

[0004] The use of the term "Complex Inorganic Color Pigments" is a
relatively recent one. These pigments have been referred to as ceramic
pigments, synthetic inorganic complexes and mixed metal oxides. They are,
in fact, all of these. Complex inorganic color pigments are man-made
materials in violet, blue, green, yellow, brown and black that are
calcined at temperatures between 800 and 1,300 degrees Celsius. In the
past, these pigments were used primarily to color ceramics. Today, they
are one of the most important pigment classes used to color plastics and
coatings. Complex inorganic color pigments are known to be heat stable,
light fast, chemically resistant and weatherable.

[0005] Colors or colorants are made up of pigments and dyes. The Color
Pigment Manufacturer's Association defines a pigment as "colored, black,
white or fluorescent particulate organic or inorganic solids that are
usually insoluble in and essentially physically and chemically unaffected
by, the vehicle or substrate in which they are incorporated. They alter
appearance by selective adsorption and/or scattering of light. Pigments
are usually dispersed in vehicles or substrates for application, as for
instance, in the manufacture of inks, paints, plastics or other polymeric
materials. Pigments retain a crystal or particulate structure
throughout."

[0006] The present invention relates to the manufacture and use of
titanate-based CICPs that have low metal loading (doping) levels compared
with traditional CICPs. Examples of titanate-based pigments, which can be
used as bases for the present invention, include the following:

[0007] C.I. Pigment Brown 24

[0008] C.I. Pigment Brown 37

[0009] C.I. Pigment Brown 40

[0010] C.I. Pigment Brown 45

[0011] C.I. Pigment Yellow 53

[0012] C.I. Pigment Yellow 161

[0013] C.I. Pigment Yellow 162

[0014] C.I. Pigment Yellow 163

[0015] C.I. Pigment Yellow 164

[0016] C.I. Pigment Yellow 189

[0017] C.I. Pigment Black 12

[0018] C.I. Pigment Black 24

[0019] The normal variety of titanate-based CICP materials in commerce
today has relatively high metal doping levels (i.e., greater than about
10% by weight). As used herein, "doping level" or "loading level" refers
to the amount of replacement by weight of TiO2 in the titanate
lattice structures. For example, C.I. Pigment Brown 24 is made of a
rutile titanium dioxide-based crystal doped with chromium (III) oxide
(coloring oxide) and antimony (V) oxide (colorless charge balancing
oxide). A typical composition of that homogeneous pigment in ceramic
nomenclature is described in the Pigment Handbook, at page 383, as
follows: Cr2O3.Sb2O5.31TiO2. In this compound,
the following are the weight percents of the component elements:

[0025] Such a formulation and other formulations with even higher metal
loadings, typically between about 10 and about 20% of the total TiO2
by weight replaced by the Cr and Sb oxides, describe a common commercial
C.I. Pigment Brown 24 pigment. Most conventional CICPs in today's
marketplace tend to have doping levels nearer to about 20% replacement
level. The reason for high levels of doping in conventional CICPs is
two-fold: first, it provides a brighter color for the pigment, and
second, it helps give the resulting pigment good tinting strength.

[0026] Doped rutile pigments are described in the following U.S. patents;
none of them describe or include examples of doping levels less than 5%:

[0027] U.S. Pat. No. 1,945,809, Herbert, issued Feb. 6, 1934

[0028] U.S. Pat. No. 2,257,278, Schaumann, issued Sep. 30, 1941

[0029] U.S. Pat. No. 3,022,186, Hund, issued Feb. 20, 1962

[0030] U.S. Pat. No. 3,832,205, Lowery, issued Aug. 27, 1974

[0031] U.S. Pat. No. 3,956,007, Modly, issued May 11, 1976

[0032] Each of the following patents describes the use of modifiers to
improve some property of the defined pigments. The '175 patent discusses
improving infrared reflectivity. None of these patents suggests doping
levels below 5%:

[0038] Finally, PCT Published Patent Application WO 2011/101657, Edwards
et al, published Aug. 25, 2011, suggests using rutile TiO2, at a
larger size than typical, in conjunction with colored organic pigments to
provide improvement in IR reflectance. Colored titanate pigments may also
be combined with organic pigments in the disclosed compositions.

[0039] Solar radiation reaching the earth's surface covers a spectral
range starting at about 300 nanometers (nm) and trailing off in the
infrared region at about 2,500 nm. Solar radiation peaks in the visible
spectral range. Still, roughly 50% of the radiation reaching the earth's
surface is in the IR spectral region. This IR radiation contributes to
heat build-up in exposed articles. Most of this results from radiation
which is absorbed by a substrate and is converted into heat, thereby
heating the entire object. An example of this would be a building, such
as a storage facility, which is built from metal sheets or even cinder
blocks, and which is located in a temperate (or even tropical) area. The
sun beating down on this building during the late Spring and Summer
months would, as a result of infrared absorption, heat the interior space
of the building, thereby affecting the materials which are stored in the
building.

[0040] In order to keep exposed surfaces cooler, efforts have been ongoing
to increase the surfaces' infrared (IR) reflectivity. The more solar IR
radiation that is reflected away from the surface, the less is absorbed
and the cooler a surface will remain upon direct exposure. Achieving
higher IR reflectance and cooler surfaces, can result in decreased energy
consumption and lower energy costs.

[0041] The present invention provides coloring materials that are useful
in boosting the solar IR reflectivity in articles in which they are used
as a pigment in place of more common and conventional pigments.

SUMMARY

[0042] The present invention relates to a complex inorganic titanate
pigment having a loading of colored metal ions and their charge-balancing
ions of less than about 5% (for example, less than about 2%) by weight,
and an average particle size of from about 0.3 to about 5 μm (for
example, from about 1 to about 3 μm).

[0043] The present invention also relates to high infrared reflective
paint (as well as other coating) compositions, as well as plastics,
ceramics, glass enamels, concrete and other systems requiring high
durability color, which comprise an effective amount of the pigment
defined above. Finally, the present invention relates to a method for
providing a surface with both visual color and high infrared reflectivity
comprising the step of coating said surface with the paint composition
defined above.

[0044] As used herein, all percentages and ratios are "by weight", unless
otherwise specified. Further, references listed in this application are
all incorporated by reference herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0045]FIG. 1 shows the reflective spectra of a paint containing a pigment
of the present invention and a control paint containing conventional
pigments, as described in Example 1.

[0046]FIG. 2 shows the reflective spectra of a paint containing a pigment
of the present invention and a control paint containing conventional
pigments, as described in Example 2.

[0047]FIG. 3 shows the reflective spectra of a paint containing a pigment
of the present invention and a control paint containing conventional
pigments, as described in Example 3.

[0048] FIG. 4 shows the reflective spectra of a colored PVC plaque
containing a pigment of the present invention and a control PVC plaque
containing conventional pigments as described in Example 4.

[0049] FIG. 5 shows the reflective spectra of a colored PVC plaque
containing a pigment of the present invention and a control PVC plaque
containing conventional pigments as described in Example 5.

[0050]FIG. 6 shows the reflective spectra of a colored PVC plaque
containing a pigment of the present invention and two control PVC plaques
containing conventional pigments as described in Example 6.

DETAILED DESCRIPTION

[0051] As used herein, the phrase "effective amount" means an amount of
pigment which can be incorporated into a paint or other product so as to
provide a desired color and IR reflectivity, without providing undesired
formulational difficulties.

[0052] Further, as used herein, the phrase "substantially free" of a
particular component, means that the defined product contains no greater
than about 5% by weight of the particular component (from which it is
said to be "substantially free"), for example, no greater than about 2%
of said component, or no greater than about 1% of said component.

[0053] The present application relates to the preparation and use of a
range of titanate-based CIPCs that contain an unusually low level (i.e.,
low loading) of coloring and charge balancing oxide metal doping
materials. The low-loading of coloring and balancing metal oxides results
in a CICP of unusually high infrared reflectivity. These low loaded CICPs
can be used alone or in combination to increase the IR reflectivity in
pigmented materials in which they are employed.

[0054] The low-loaded titanate-based CIPCs of the present invention
include less than about 5% by weight of coloring and charge balancing
metal oxide components. Exemplary embodiments of the materials include no
greater than about 4% of such doping elements; less than about 2% of such
doping elements; or no greater than about 1% of such doping elements.
These levels are considered low in comparison to commercially-available
CICP materials.

[0055] In preparing the CICPs of the present invention, the pure
constituent oxides are dry-blended together to form a raw material blend.
This blend is calcined at temperatures between about 800° C. and
about 1,300° C., for about 4 to about 12 hours. The calcined
product is cooled and milled to a pigmentary particle size
post-calcining. For example, jet milling, pulverizing and other particle
size reduction techniques known in the art can be used. The particles
produced may have an average size of from about 0.3 to about 5 microns in
diameter, for example, from about 0.5 to about 5 microns, from about 1 to
about 5 microns, or from about 1 to about 3 microns in diameter.

[0056] Once prepared, the pigment is employed in coloring a substrate in
order to impart visual color and also to provide maximum IR reflectance
for the given visual color. High IR reflectivity is required in
circumstances where avoiding excessive heat buildup from exposure to
ambient sunlight is desirable. CICPs are generally used in demanding
applications where resistance to chemicals, weather, light and heat are
required. The present invention is particularly useful for, but not
limited to, these types of applications.

[0057] The pigments of the present invention may be used as the sole
colorant in a composition or may be used in combination with other dyes
and/or pigments. In one embodiment, the composition contains a pigment of
the present invention and is substantially free of organic pigments.

[0058] The CICPs described herein may be used, for example, as the
coloring element in paint compositions or as the coloring element in
objects, such as plastic, ceramic, concrete or glass enamel objects,
which require coloration. The manner of formulating such objects is
well-known to those skilled in the art. In a paint composition, the
pigment is blended with a paint vehicle and other conventional paint
components which are well-known to those skilled in the art. Examples of
such conventional paint components include: binders; vehicles; solvents;
modifiers of surface tension, flow properties, foaming, wet edge,
skinning, antifreeze properties and pigment stability; catalysts;
thickeners; stabilizers; emulsifiers; texturizers; adhesion promoters; UV
stabilizers; flatteners (de-glossing agents); and biocides.

[0059] In one embodiment of the present invention, a paint composition is
formulated so as to contain, as pigment materials, only the low-loaded
pigments of the present invention, and is substantially free of any other
pigment materials. Further, in an embodiment of the present invention,
the paint composition is formulated so as to contain, as pigment
materials, low-loaded pigments of the present invention and be
substantially free of all other titanate-derived pigment materials.

[0060] In commercially-available (prior art) CICPs, the high metal
loadings used to maximize color and tinting strength result in the
absorption bands that yield the desired visual color to become stronger
and broadened over a larger spectral scale. This effect makes the
commercial pigments less reflective visually but, more importantly, less
reflective in the IR spectral region. This effect is intrinsic to the
pigment and is not fully overcome by adding more titanium dioxide white
in a color match. To state this more specifically, a low-loading CICP, as
defined in the present application, will be more reflective than an
equivalent combination of a common (prior art) commercial grade of the
CICP together with TiO2 white. This fundamental difference is where
the usefulness of the present invention is observed. Low-loading CICPs,
as defined herein, can be used to make more infrared reflective color
combinations. This is best shown by the examples of the reflection curves
of the common commercial CICPs compared with the low loading CICPs of the
present invention, illustrated in FIGS. 1-6.

[0061] Most opaque colors are made using a combination of pigments. Simple
colors, such as tints, are combinations of a color pigment plus a white
pigment, most typically TiO2 white. More complex colors use a larger
number of pigments. Multiple formulations can yield virtually the same
visual color. However, pigments have a wide variety of infrared
reflectivities and the choice of pigment in a particular color match can
have a large impact on the overall IR reflectivity of the resulting
color.

[0062] Set forth below are some specific examples of the present
invention. These examples are merely illustrative compositions that can
be made utilizing the present invention. It is not in any way intended
that the scope of the present invention be limited by such examples.

[0063] In this example, a low-loading C.I. Pigment Brown 45 is prepared by
dry blending pigment grade oxide powders of TiO2, Mn3O4,
and WO3 in a ratio of 425TiO2:2WO3:1Mn3O4. The
dry blends were calcined in air for 5 hours at 1,100 C, yielding a
uniform light brown powder. The calcined powder is finish milled to
reduce the average particle size to a range of 1 to 3 microns. This
synthesis prepares a pigment grade material containing 98% TiO2.

[0064] The prepared low-loading Pigment Brown 45 is made into a
commercially available acrylic automotive paint or coating for
evaluation. An example would be PPG DMR 499 resin. Test paints were made
to have 28.5% pigment in liquid paint. For evaluation, the paint is drawn
down in a uniform film using, for example, a 10-mil bird gauge, yielding
a visually opaque dry film containing 55% pigment that is between 2 and 3
mils in film thickness.

[0065] A similar visually colored paint or coating is prepared from a
blend of common conventional pigments; TiO2 white, C.I. Pigment
Green 17, C.I. Pigment Red 101, and C.I. Pigment Brown 24. This blend of
pigments, called a color match, is made into an acrylic paint or coating
at 28.5% pigment total pigment. The paint is drawn down in a uniform film
using a 10-mil bird gauge, yielding a visually opaque dry film containing
55% pigment that is between 2 and 3 mils in film thickness.

[0066] To compare the two films, the reflective spectra of each is
measured in the 300 to 2,500 nm spectral range. The spectra are shown in
FIG. 1. Also included in FIG. 1 is a mapping of the intensity of the
solar radiation at the earth's surface as a function of wave length
(using a relative scale).

[0067] From the spectral plot it can be seen that the low-loaded pigment
Brown 45 of the present invention makes a color which is more reflective
in the IR wavelengths, when compared to the paint formulated with
conventional pigments. A measure of the importance of this difference can
be seen by looking at the plot of relative intensity of sunlight at the
earth's surface which is included for reference. It can be seen that the
sunlight intensity is highest in the shorter IR wave lengths from 700 to
900 nm. In this region, the low-loaded pigment Brown 45 shows the
greatest difference and advantage in IR reflectivity when compared with
the conventional pigment match.

[0068] One way to numerically compare one color vs. another in solar
reflectivity is to use a device to measure the total solar reflectivity.
Such a device, called an SSR-ER (for example, the one sold by Devices &
Services, a Solar Spectrum Reflectometer, Model SSR-ER), can provide a
comparative number that is defined as Total Solar Reflectivity (measured
as a percent). % TSR, which means Total Solar Reflectance, takes
reflectance values for the wave length range 200-2,500 nm (solar energy)
and applies the solar incident radiation, weighted for each wave length.
This value is used to determine how hot a color will be in the sunlight
and to rank colors against each other in terms of heat absorption and
high IR reflectivity. The higher the % TSR value, the more a sample
reflects sunlight. In Example 1, the low-loaded Brown 45 has a % TSR
value of 52%, while the visual color match has a % TSR of 46%.

[0069] In this example, a low-loading C.I. Pigment Yellow 162 is prepared
by dry blending pigment grade oxide powders of TiO2,
Cr2O3, and Nb2O5 in a ratio of
312TiO2:1Nb2O5:1Cr2O3. The dry blends were
calcined in air for 5 hours at 1,170 C, yielding a uniform light yellow
powder. The calcined powder is finish milled to reduce the average
particle size to a range of 1 to 3 microns. This synthesis prepares a
pigment grade material containing 98% TiO2.

[0070] The prepared low-loaded Pigment Yellow 162 is made into a
commercially available acrylic automotive paint or coating for
evaluation. An example would be PPG DMR 499 resin. Test paints were made
to have 28.5% pigment in liquid paint. For evaluation, the paint is drawn
down in a uniform film using, for example, a 10-mil bird gauge, yielding
a visually opaque dry film containing 55% pigment that is between 2 and 3
mils in film thickness.

[0071] A similar visually colored paint or coating is prepared from a
blend of common conventional pigments; TiO2 white, C.I. Pigment
Yellow 53, C.I. Pigment Red 101, and C.I. Pigment Brown 24. This blend of
pigments, called a color match, is made into an acrylic paint or coating
at 28.5% pigment total pigment. The paint is drawn down in a uniform film
using a 10-mil bird gauge, yielding a visually opaque dry film containing
55% pigment that is between 2 and 3 mils in film thickness.

[0072] The reflective spectra of each of these paints is measured. The
spectra are shown in FIG. 2.

[0073] The low-loaded Pigment Yellow 162 yields a color with more IR
reflectivity when compared to the conventional pigment match composition.
The low-loaded Pigment Yellow 161 has a % TSR value of 66%, while the
conventional pigment match has a % TSR of 63%.

[0074] In this example, a low-loading C.I. Pigment Yellow 163 is prepared
by dry blending pigment grade oxide powders of TiO2,
Cr2O3, and WO3 in a ratio of
554TiO2:1WO3:1Cr2O3. The dry blends were calcined in
air for 5 hours at 1,100 C, yielding a uniform light brown powder. The
calcined powder is finish milled to reduce the average particle size to a
range of 1 to 3 microns. This synthesis prepares a pigment grade material
containing 99% TiO2.

[0075] The prepared low-loaded Pigment Yellow 163 is made into a
commercially available acrylic automotive paint or coating for
evaluation. An example would be PPG DMR 499 resin. Test paints were made
to have 28.5% pigment in liquid paint. For evaluation, the paint is drawn
down in a uniform film using, for example, a 10-mil bird gauge, yielding
a visually opaque dry film containing 55% pigment that is between 2 and 3
mils in film thickness.

[0076] A similar visually colored paint or coating is prepared from a
blend of common conventional pigments; TiO2 white, C.I. Pigment
Yellow 53 and C.I. Pigment Brown 24. This blend of pigments called a
color match, is made into an acrylic paint or coating at 28.5% pigment
total pigment. The paint is drawn down in a uniform film using a 10-mil
bird gauge, yielding a visually opaque dry film containing 55% pigment
that is between 2 and 3 mils in film thickness.

[0077] The reflective spectra of each of these paints can be measured.
These are shown in FIG. 3.

[0078] The low-loaded Pigment Yellow 163 yields a color with more IR
reflectivity compared to the pigment made with the conventional color
match pigment. The low-loaded Pigment Yellow 163 has a % TSR value of
70%, while the color match pigment has a % TSR of 66%.

[0079] In this example, a low-loading C.I. Pigment Yellow 164 is prepared
by dry blending pigment grade oxide powders of TiO2,
Mn3O4, and Sb2O3 in a ratio of
164TiO2:2Sb2O3:1Mn3O4. The dry blends were
calcined in air for 5 hours at 1,050 C, yielding a uniform light brown
powder. The calcined powder is finish milled to reduce the average
particle size to a range of 1 to 3 microns. This synthesis prepares a
pigment grade material containing 98% TiO2.

[0080] The prepared Pigment Yellow 164 is made into a commercially
available rigid PVC plaque for evaluation. An example would be Georgia
Gulf Type 3304-AT00. Test plaques were made to have a total of 5% pigment
in the finished plaque. For evaluation, the pigment and PVC resin are dry
mixed then melted and press-molded to form a flat plaque for color and
reflectivity measurements.

[0081] A similar visually colored PVC plaque is prepared from a blend of
common conventional pigments: TiO2 white, C.I. Pigment Yellow 164,
C.I. Pigment Red 101, and C.I. Pigment Brown 24. This blend of pigments,
called a color match, is made into a PVC plaque at 5% total pigment, as
above. The plaque is made in a similar method to that mentioned above for
evaluation.

[0082] The reflectance curves for the samples, prepared above, are shown
in FIG. 4. The low-loading Pigment Yellow 164 yields an equivalent visual
color with more IR reflectivity compared to the conventional pigment
match. Examination of the reflectance curves shows the greater IR
reflectivity of the low-loading Pigment Yellow 164 in the spectra region
from 600 to 1,000 nm. As a result of this difference, the low-loading
Pigment Yellow 164 has a % TSR value of 55%, while the conventional
pigment match measures lower at 53%.

[0083] In this example, a low-loading C.I. Pigment Brown 24 is prepared by
dry blending pigment grade oxide powders of TiO2, Cr2O3,
and Sb2O3 in a ratio of
164TiO2:2Sb2O3:1Cr2O3. The dry blends were
calcined in air for 5 hours at 1,050 C, yielding a uniform light yellow
powder. The calcined powder is finish milled to reduce the average
particle size to a range of 1 to 3 microns. This synthesis prepares a
pigment grade material containing 98% TiO2.

[0084] The prepared Pigment Brown 24 is made into a commercially available
rigid PVC plaque for evaluation. An example would be Georgia Gulf Type
3304-AT00. Test plaques were made to have a total of 5% pigment in the
finished plaque. For evaluation, the pigment and PVC resin are dry mixed
then melted and press-molded to form a flat plaque for color and
reflectivity measurements.

[0085] A similar visually colored PVC plaque is prepared from a blend of
common conventional pigments: TiO2 white, C.I. Pigment Yellow 53,
C.I. Green 17, and C.I. Pigment Brown 24. This blend of pigments, called
a color match, is made into a PVC plaque at 5% total pigment as above.
The plaque is made in a similar method to that mentioned above for
evaluation.

[0086] The reflectance curves for the samples, prepared above, are shown
in FIG. 5. The low-loading Pigment Brown 24 yields an equivalent visual
color with more IR reflectivity compared to the conventional pigment
match. Examination of the reflectance curves shows the greater IR
reflectivity of the low-loading Pigment Yellow 164 in the spectra region
from 650 to 850 nm. As a result of this difference, the low-loading
Pigment Yellow 164 has a % TSR value of 70%, while the conventional
pigment match measures lower at 68%.

[0087] In this example, a low-loading C.I. Pigment Yellow 164 is prepared
by dry blending pigment grade oxide powders of TiO2,
Sb2O3, Mn3O4, and WO3, in a ratio of
173TiO2:1.1Sb2O3:1Mn3O4:0.2WO3. The dry
blends were calcined in air for 5 hours at 1,000 C, yielding a uniform
light brown powder. The calcined powder is finish milled to reduce the
average particle size to a range of 1 to 3 microns. This synthesis
prepares a pigment grade material containing 96% TiO2.

[0088] The prepared Pigment Yellow 164 is made into a commercially
available rigid PVC plaque for evaluation. An example would be Georgia
Gulf Type 3303-AT00. Test plaques were made to have a total of 5% pigment
in the finished plaque. For evaluation, the pigment and PVC resin are dry
mixed then melted and press-molded to form a flat plaque for color and
reflectivity measurements.

[0089] For comparison, two similar visually colored PVC plaques are
prepared from a blend of common conventional pigments of similar color
space also used in PVC siding. The samples of traditional pigments are
cut with TiO2 white in order to produce a color with equal
light/dark value (equal L* value) for this comparison.

[0090] The first sample is made from a mixture of 69% TiO2 white and
31% C.I. Pigment Brown 33. The blend of pigments is made into PVC plaque
at 7.2% total pigment, as above. The plaque is made in a similar method
to that described above for evaluation.

[0091] The second plaque is prepared from a mixture of 80% TiO2 white
and 20% C.I. Pigment Black 12. The blend of pigments is made into PVC
plaque at 6.2% total pigment, as above. The plaque is made in a similar
method to that described above for evaluation.

[0092] The reflectance spectra of each PVC plaque was measured. These are
shown in FIG. 6.

[0093] All six of these examples demonstrate that the pigments of the
present invention, and particularly paint or plastic compositions
formulated using those pigments, exhibit a higher infrared reflectance
when compared with conventional pigments formulated so as to match the
color of the pigment of the present invention.

[0094] Similar results are seen using other low-loaded titanate pigments
of the present invention, or when the low-loaded pigments are used in,
for example, other types of paint, plastic, ceramic, glass enamel or
concrete formulations.